It is pretty simple which part are u confused by?
Oxygen and carbon dioxide travels to and from tiny air sacs in the lungs, through the walls of the capillaries, into the blood. Blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs.

Body temperature, Environmental temperature, Body mass, Reproductive condition, Activity, Feeding, Body condition, Season. All of these would help increase it. Hope this helps. :)
For most athletes, the period in their
yearly training cycle during which it is recommended to begin calorie restriction
so as to lose significant amounts of stored body fat is the off-season or early
in the preseason. Restriction of energy intake late in the preseason when
there is rigorous training or during season when there is competition may impede training, recovery,
or performance.
I believe the answer is a mineral's crystal shape is determined by its atomic structure.